Known arrangements for encoding information on labels (or other items) use one-dimensional codes with a binary optical pattern. An example thereof is the so-called “barcode” or Universal Product Code (UPC) used to identify products at the point of sale or used for inventory control purposes. Binary optical patterns allow only two possible reflectance values. Such arrangements typically make use of a white background and black printed markings in a required pattern, representing binary “0” and “1” respectively. The information is encoded in the widths and frequency of the black lines on the white background.
More recently, in order to increase the data density and/or reduce the label sizes used, two-dimensional codes were developed. However, most of these arrangements were mere two-dimensional embodiments of the one-dimensional codes in that they also make use of binary optical patterns. These arrangements utilise patterns of black dots or squares/rectangles instead of lines on a white background.